The present invention relates to a magazine for use in a library of hard disk drives.
Large scale computing devices often employ a library of removable computer memory media to provide for increased storage capability and the sharing of media by multiple hosts. In such a library, the media are shelved in storage bins for retrieval by a robotic picking apparatus or xe2x80x9cpicker.xe2x80x9d Such a picker for optical disk media is described in Dimitri et al., U.S. Pat. No. 5,377,121, which is herein incorporated by reference in its entirety. Tape cassettes are another common library media. The library has at least one drive receptacle coupled to one or more host computers that may read or write to the media.
When a host requests a particular medium in the library, the picker is typically commanded to travel to the storage bin in the library where the medium is shelved, grip the medium, remove the medium from the storage bin, travel to a destination drive having input/output (xe2x80x9cI/Oxe2x80x9d) connections with the host, insert the medium into the drive, and power the drive.
A problem with these prior art libraries is that optical media provides relatively slow reading and writing, while tape media provides relatively slow random access.
In recognition of these problems, the concept of a library of hard disk drives was developed, which is the subject of the assignee""s companion application entitled LIBRARY OF HARD DISK DRIVES WITH TRANSPARENT EMULATING INTERFACE, executed on Apr. 9, 2001 by inventors Kamal Dimitri, Robert G. Emberty, Craig Klein, and Daniel J. Winarski, filed on Apr. 26, 2001, and incorporated herein by reference in its entirety. According to the concept, hard disk drives are stored in associated storage locations in the library. The robotic picker is adapted to couple and decouple a selected disk drive from a destination receptacle that is coupled to the one or more host computers requesting data.
The hard disk drive library provides the advantage of relative speed as compared to libraries employing optical or tape media. Entire hard disk drives, rather than hard disk media, are exchanged in the library to remain within the close mechanical tolerances required for efficient use of this memory element.
In a basic form of the concept, the destination receptacle provides power connections to the disk drive and I/O connections to the host computers, and the robotic picker retrieves the selected disk drive from its storage location, carries the disk drive to and inserts the disk drive into the destination receptacle. The disk drive is then powered and spins up to its operating speed. Finally, when this operating speed is reached, the data on the disk drive may be accessed by the computer.
As may be readily appreciated, all of this movement takes time, and efforts are constantly being made to decrease the time required to access memory elements in the library.
Disk drives are often virtually combined in a method known in the art as RAID (xe2x80x9credundant array of independent disksxe2x80x9d), to gain speed, redundancy, or both. However, the disks in the array are physically separate and distinct from one another and are stored separately in the library, and installed into or removed from the destination backplane separately by the picker as aforedescribed. Therefore, although the computer may treat the RAID array as a single disk, the time required to set up the array for use by the computer is multiplied by the number of disks in the array. Moreover, as the connections to the destination backplane must be made separately for each of the disks in the array, the reliability of connecting the array is reduced from that of a single disk.
Accordingly, there is a need for a magazine for a plurality of removable disk drives that provides for decreasing the time and increasing the reliability of loading and unloading an array of disks in a disk drive library.
The magazine for a plurality of removable disk drives of the present invention solves the aforementioned problems and meets the aforementioned needs by providing physical and electrical support for the plurality of disk drives. The magazine includes a magazine backplane for electrically connecting to the disk drives, and a module connector for electrically connecting to a host computer, preferably at a backplane of the library. Preferably, the magazine also supports a connecting circuit for implementing a fibre channel arbitration loop and intelligent hub for reconfiguring the fibre channel arbitration loop if one or more of the disk drives fails.
Therefore, it is a principal object of the present invention to provide a magazine for a plurality of removable disk drives.
It is another object of the present invention to provide a magazine for a plurality of removable disk drives that provides for interconnecting the plurality of disk drives with a computer with a single connection.
It is yet another object of the present invention to provide a magazine for a plurality of removable disk drives that provides for interconnecting the plurality of disk drives as a RAID and a computer with a single connection.
It is still another object of the present invention to provide a magazine for a plurality of removable disk drives that provides a selection mechanism supported by the magazine for altering the electrical interconnection between the disk drives and the computer.
It is a further object of the present invention to provide a magazine for a plurality of removable disk drives that provides for its transportation by a robotic picking device.
The foregoing and other objects, features and advantages of the present invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the following drawings.